Typically, I see code like:

```
Quaternion _exampleQuaternion = Quaternion.Euler(0,180,0);
```

So my question is: How do the parameters in the Quaternion constructor affect an object, what are the parameters angle limits, and when should manual construction be used?

Also… I know Squirrel Eiserloh says that the *w* in the 4-D rotation stands for *“Witchcraft”* but is there a more concrete explanation for this odd creature?

(((O)))

The above code does not use a Quaternion constructor. It is a class method that creates a Quaternion for you. There are no angle limits that I am aware of. I’ve never needed to construct a Quaternion directly and never seen a answer posted to this list that required a direct construction of a Quaternion. You’d have to go a more scholarly direction to understand the 4D matrix and the w parameter:

http://en.wikipedia.org/wiki/Quaternion

And I second @alucardj’s suggestion of Unity Gems as a place to start with Quaternions in Unity.